CNC Knurling tool

[John Stevenson]

Just bought one of these off Ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...tem=3831144764

Anyone have any experiance of these?
They work by cutting the knurl as opposed to squashing the pattern on.
I did a web search and found some info on the Dorian one.
They also do a straight knurl that carries one diagonal wheel at the same helix angle so it cuts straight.

http://www.doriantool.com/Knurling/knrl_b7.pdf

After I've had a play with this toy I might attempt to do a straight one.

I often need long straight knurls for the motor shafts to be pressed into the rotors.


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John S.
Nottingham, England

[DR]

John,

I've tried without much success to use the Hardinge version of cut knurling tool. Of course, it isn't as fancy as yours. On the Hardinge tool the wheels are not as easily adjustable.

My worst results were in aluminum, but aluminum is a very difficult material to cleanly knurl. (Occasionally I make some high end knurled musical instrument parts, until I got into those parts I assumed aluminum was a piece of cake which it isn't. Since these parts I've come to notice aluminmum knobs, very few are knurled, most are extruded with straight "knurl" pattern).

In my experience nothing beats the opposed knurl type setup, a quick pass at high feedrate and you've got perfect knurls everytime. My favorite is one off a B&S screw machine. For engine lathe work my favorite is the scissor type from Eagle Rock.

[ibewgypsie]

DO you know I envy you cause you got more toys to play with than I do.

At least you are on the other side of the pond so you can't rub it in person.. HA..



[This message has been edited by ibewgypsie (edited 11-09-2005).]

[DR]

Uh, David?

"Major tool purchases... WHOO HOOO..... "

Toys to play with? What the heck are you talking about? In my locale the prices you paid would constitute a felony.

[spope14]

For CNC Knurling, or even manul, that is a good tool, but centering on a manual machine to get the "perfect knurl" is hard on a manual.

I also prefer the "Eagle rock" Scissor knurl for maunal lathes, I can knurl anything perfectly, have a little system I use that I can share sometime for the eagle rocks. 99% of my knurls come out perfect, on anything from tool steel to aluminum to delrin. The seceret is "touch", and plenty of cutting fluids.

As for CNC, I also use a "bump Knurl", much like the old "armstrong' type, that has the head that rocks or "self centers". The secret on CNC Knurling with these bad boys is the feed into the part, and multi passes that allow the knurler to find its center and "timing', then on my back and forth passes, allows for cutting and the pressing, and gives time for the materials to "work in".

I love knurling and threading.


Sounds slow, actually very quick

[John Stevenson]

Just got the tool this morning and had a quick play before I had to go out.
I know the knurl wouldn't be any good as it has odd wheels in.
I was more concerned about what pressure was needed.
Plunged in at the end of a 1" bar and fed along, hardly any pressure needed as it's only touching on the very edges of the wheels.

As it feeds you can see little chips being thrown off.
Put flood coolant on and set the speed for 300 rpm and it was cutting nice.
Did about an inch and as expected one hand is courser than the other but taking each hand seperatly they are very clean and well defined.

There are two adjustments on this one, diameter from 1/8" up to 10" which alters the helix angle and a push / push setup with two locking screws to centralise on the work.

I need to make a couple of small spacers up to handle the knurl wheels I have and have another try later.

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John S.
Nottingham, England

[Paul Alciatore]

I always see something new and interesting here.

Price sounds a bit steep for my pocketbook.

So, are those standard knurls? It looks like their edges are actually being used as cutting tools. Wouldn't they have to be sharpened for this? Or do they just "plow through"?

Let us know how it works with new knurls.

Paul A.

[John Stevenson]

Just made the spacers to accept the knurls I have. Paul is right, these cut on the very edge so I faced them off on the surface grinder to get rid of the chamfer and leaft a sharp edge.
No problem with being hard as knurl wheels are High Speed Steel.
Works OK now but up to a limit.

The original wheels were 20mm diameter, the ones I have are only 5/8" so it's cocked up the settings dial and I can't get below about 3/4" diameter but it's now cutting an equal knurl with hardly any pressure to speak of as it only uses a knife edge.
Running at 300 rpm with a very fast feed, probably ten times what a pressure knurl will stand, one pass.

Photo's later, got a large rotor snapped in two and that pays better but I'll order some better knurls tonight from J&L and play again later.
I'm impressed enought to want to go for a single straight knurl design like in the second link I posted.

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John S.
Nottingham, England

[gglines]

spope14:

I use the Eagle Rock knurler on my manual lathe and get good results. I'd be interested in your system you mentioned if you wouldn't mind sharing?

Thanks,

George

[John Stevenson]

Damn it,
Just rushed in from the shop, full of good news and cheer and the bloody memory stick on the camera has got Altzhimers.
Either that or the rain has washed the pictures off in the mad dash from the workshop.

Later, gotta find me a torch and go look for the pictures that's slid off the memory stick......must be on the path........

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John S.
Nottingham, England

[Mark Jones]

Here's a tip that really works with them cards for cameras...well it's worked everytime for me ...
take it out lick the gold area .....then wipe it on a clean pair of jeans.
Plonk it back in your camera or card reader and bingo its fixed.
all the best.....mark

[Alistair Hosie]

huh when did you ever own a clean pair of jeans?.or scants for that matter will phone u tomorrow

[wierdscience]

John,seeing as how you stole that knurling tool,you should at least buy a set of knurls Poor buggers that made it are probibly hungry

[John Stevenson]

Weird,
I have bought some new knurls for it, that's what the pics were.
Anyway I didn't steal it 51 quid is a lot here.

Here's a steal

http://cgi.ebay.co.uk/ws/eBayISAPI.d...tem=3832801289


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John S.
Nottingham, England

[wierdscience]

Dunno if its the same brand but a cut-knurling holder is about$645 here,so yes you did steal it

Thats a spiffy looking boring head,but whats with the external thread?Some kind of oddball retention device?